WHM / cPanel : 550 Please turn on SMTP Authentication in your mail client

ERROR:- The response from the remote server was: 550 Please turn on SMTP Authentication in your mail client. mail-qk1-f172.google.com [209.85.222.172]:36503 is not permitted to relay through this server without authentication. SOLUTION:- Manage SMTP restrictions Click Enable to deny users the ability to bypass your mail server to send mail. To allow users the ability to bypass your…